Electronic camera

ABSTRACT

An object of the invention is to provide an electronic camera that can properly display a moving image usable as a viewfinder. The electronic camera of the invention includes: an image pickup section photographing an object for image generation; a display device displaying the image generated by the image pickup section as a moving image; a buffer section; a recording section; and a display switching section. The buffer section temporarily stores the image generated by the image pickup section and to be displayed as a moving image on the display device. The recording section records the image generated by the image pickup section according to a user&#39;s operation. The display switching section switch, at predetermined timing, a first display for display of a moving image on the display device through the buffer section, and a second display for display of a moving image not through the buffer section.

TECHNICAL FIELD

The present invention relates to an electronic camera having a displaydevice.

TECHNOLOGICAL BACKGROUND

There have been conventional electronic cameras having a function ofdisplaying, on a display device, a moving image that can be used as aviewfinder. Among these electronic cameras, a type of camera is known,in which the following two different buffers, two for each, are providedfor driving an internal image sensor, an internal display device, andthe like in response to a video synchronizing signal (hereinafter,referred to as a V-signal).

One type is a buffer used for temporarily storing data of a moving imagegenerated by the image sensor or the like (hereinafter, referred to as abuffer for photographed image). The other type is a buffer used fortemporarily storing data of a moving image to be displayed on thedisplay device (hereinafter, referred to as a buffer for display image).

In such an electronic camera, while moving image data is being storedinto one buffer for photographed image in response to a V-signal, themoving image data that has been stored in the other buffer forphotographed image in response to the previous V-signal is transferredto one buffer for display image. Similarly, while the moving image datais being transferred to one buffer for display image, the moving imagedata that has been stored in the other buffer for display image inresponse to the previous V-signal is displayed on the display device.

To display a moving image by use of the buffers for photographed imageand for display image, however, the time for three cycles of theV-signal is required from when the image sensor begins to generate imagesignals associated with the moving image data until the image signalsare displayed on the display device as a moving image. Accordingly, amoving image displayed on the display device is always the image of anobject that occurred three cycles of the V-signal earlier.

Therefore, when the user takes a picture, seeing not an object but amoving image, it is hardly possible to release the shutter at the rightmoment due to the above-described delay of displaying the moving image.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide an electronic camerathat can properly display a moving image usable as a viewfinder.

Hereinafter, claims of the invention will be described on anitem-by-item basis.

(1) An electronic camera of the invention includes an image pickupsection, a display device, a buffer section, a recording section, and adisplay switching section. The image pickup section photographs anobject to generate an image. The display device displays the imagegenerated by the image pickup section as a moving image. The buffersection temporarily stores therein the image generated by the imagepickup section and to be displayed as a moving image on the displaydevice. The recording section records thereon the image generated by theimage pickup section according to a user's operation. The displayswitching section switches, at a predetermined timing, a first displayfor display of a moving image on the display device through the buffersection, and a second display for display of a moving image not throughthe buffer section.

(2) The electronic camera of the invention may preferably have thefollowing features. First, the camera includes an operating member whichreceives in two steps a user's operation associated with the imagerecording by the recording section. Second, the camera includes ashooting condition adjusting section which performs at least either autoexposure adjustment or autofocus until the operating member is pressedin a first step. Third, the display switching section performs the firstdisplay until the operating member is pressed in the first step, andswitches the first display to the second display when a release buttonis pressed in the first step.

(3) The electronic camera of the invention may preferably have thefollowing features. First, the camera includes an exposure adjustingsection which performs auto exposure adjustment. Second, the cameraincludes an operating member which receives a user's operation to stopthe auto exposure adjustment. Third, the display switching sectionperforms the first display until the user's operation to stop the autoexposure adjustment is received by the operating member, and switchesthe first display to the second display when the user's operation tostop the auto exposure adjustment is received.

(4) Further, the electronic camera of the invention may preferably havethe following features. First, the camera includes a focusing sectionwhich performs autofocus.

Second, the camera includes an operating member which receives a user'soperation to stop the autofocus. Third, the display switching sectionperforms the first display until the user's operation to stop theautofocus is received by the operating member, and switches the firstdisplay to the second display when the user's operation to stop theautofocus is received.

(5) Further, the electronic camera of the invention may preferably havethe following features. First, the camera includes an exposure adjustingsection which performs auto exposure adjustment. Second, the cameraincludes a focusing section which performs autofocus. Third, the cameraincludes an operating member which receives a user's operation to stopthe auto exposure adjustment and autofocus. Fourth, the displayswitching section performs the first display until the user's operationto stop the auto exposure adjustment and autofocus is received by theoperating member, and switches the first display to the second displaywhen the user's operation to stop the auto exposure adjustment andautofocus is received.

(6) Further, the electronic camera of the invention may preferably havethe following feature that the display switching section decides whetheror not to enable the second display according to the user's operation.

The objects and features of the invention will become more apparent fromthe following detailed description when read in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of an electronic camera accordingto the present invention;

FIG. 2 is a flowchart of the operation of the electronic cameraaccording to the invention;

FIG. 3 is a flowchart of the operation of the electronic cameraaccording to the invention;

FIG. 4 is a drawing describing a normal display;

FIG. 5 is a drawing describing a quick display;

FIG. 6 is a flowchart of the operation of an electronic cameracorresponding to another embodiment according to the invention; and

FIG. 7 is a flowchart of the operation of the electronic cameracorresponding to the another embodiment according to the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the invention will now be described with reference to thedrawings.

Structure of the Embodiment

FIG. 1 is a functional block diagram of an electronic camera accordingto the present invention. As shown, the electronic camera 1 includes acontrolling section 10, a lens 11, an aperture 12, an image sensor 13,an image processing section 14, a display controlling section 15, adisplay device 16, a compressing/recording section 17, a TG (timinggenerator) 18, and an operation section 19. The image processing section14 includes a moving image processing section 30, a switch SW-a, a firstbuffer for photographed image 31, a second buffer for photographed image32, a switch SW-b, a switch SW-c, a first buffer for display image 33, asecond buffer for display image 34, a switch SW-d, a still imageprocessing section 35, and a still image buffer 36.

The controlling section 10 controls the system of the electronic camera1 as described below.

First, the controlling section 10 is connected through a lens drivingsection (not shown) to the lens 11, and performs AF (autofocus) on thebasis of the data supplied from an AF sensor (not shown) or the like.

Second, the controlling section 10 is connected through an aperturedriving section (not shown) to the aperture 12, and performs AE (autoexposure adjustment) on the basis of the data supplied from a photometrysection (not shown) or the like.

Third, the controlling section 10 is connected to each section withinthe image processing section 14, the display controlling section 15, thecompressing/recording section 17, the TG 18, and the operation section19, and inputs various control signals such as the V-signal output fromthe TG 18 to each section to control the driving timings and the likefor the image processing section 14, the display controlling section 15,and the compressing/recording section 17.

Forth, the controlling section 10 constantly monitors the states ofswitches constituting the operation section 19. The switches (not shown)may include, for example, a power supply switch, a release button thatcan be depressed in two steps by a half-press and full-press, an AE/AFlock switch used for forcibly locking the AE and AF, and switches usedfor changing various modes.

The image sensor 13 is connected to the TG 18, and is driven inaccordance with various control signals output from the TG 18 to supplythe image processing section 14 with image signals generated based onlight incident through the lens 11 and the aperture 12.

The moving image processing section 30 in the image processing section14 performs various image processing for a moving image on the imagesignals supplied from the image sensor 13 to generate the moving imagedata. The generated moving image data is stored through the switch SW-ainto the first buffer for photographed image 31 or the second buffer forphotographed image 32. The moving image data is then stored through theswitches SW-b and SW-c into the first buffer for display image 33 or thesecond buffer for display image 34, after which the data is supplied tothe display controlling section 15 via the switch SW-d. Alternatively,after the moving image data has been stored into the first buffer forphotographed image 31 or the second buffer for photographed image 32,the data is directly supplied to the display controlling section 15 viathe switches SW-b, SW-c (position c3 thereof), and SW-d.

The still image processing section 35 in the image processing section 14performs various image processing for a still image on the image signalssupplied from the image sensor 13 to generate the still image data. Thegenerated still image data is supplied through the still image buffer 36to the display controlling section 15 and the compressing/recordingsection 17.

The display controlling section 15 converts the moving image data andstill image data, both supplied as described above, to display data tobe displayed on the display device 16.

The compressing/recording section 17 compresses the still image datasupplied as described above and converts it to record data to be storedinto a memory card 50 (removable memory card).

Description of Operations in Embodiment

To simplify the description below, four terms are defined as follows.

First, a series of processes is referred to as moving image capturingprocess, in which moving image data is generated by the moving imageprocessing section 30 by using the image signals generated by the imagesensor 13, to store the generated moving image data through the switchSW-a into the first buffer for photographed image 31 or the secondbuffer for photographed image 32.

Second, a process in which the moving image data stored in the firstbuffer for photographed image 31 or the second buffer for photographedimage 32 is transferred to and stored into the first buffer for displayimage 33 or the second buffer for display image 34 via the switches SW-band SW-c is referred to as transmittal between buffers.

Third, a process in which the moving image data stored in the firstbuffer for display image 33 or the second buffer for display image 34 issupplied to the display controlling section 15 via the switch SW-d andthen displayed on the display device 16 is referred to as moving imagedisplaying process. Similarly, a process in which the moving image datastored in the first buffer for photographed image 31 or second bufferfor photographed image 32 is supplied through the switches SW-b, SW-c(position c3 thereof), and SW-d to the display controlling section 15and then displayed on the display device 16 is also referred to asmoving image displaying process.

Fourth, a series of processes is referred to as still image recordingprocess, in which the still image data is generated by the still imageprocessing section 35 by using the image signals generated by the imagesensor 13 and the generated still image data is supplied through thestill image buffer 36 to the compressing/recording section 17 and thenstored into the memory card 50. The still image recording process mayinclude a process in which the still image data is supplied to thedisplay controlling section 15 and then displayed on the display device16.

FIG. 2 and FIG. 3 are flowcharts of the operation of the above-describedelectronic camera, and more particularly, showing the operation of thecontrolling section 10 after the power supply switch has been turned onby a user. Referring to FIG. 1, the operation of the electronic camera 1will be described in order of the step numbers shown in FIG. 2 and FIG.3.

[Step S1]

The controlling section 10 decides whether a V-signal is input or not.The controlling section 10 repeats the operation in step S1 until aV-signal is input, and proceeds to the operation in step S2 when theV-signal is input.

[Step S2]

The controlling section 10 switches the state of each switch in theimage processing section 14 as follows.

First, immediately after the power supply switch is turned on, thecontrolling section 10 closes the switch SW-a to the position a1, switchSW-b to the b2, switch SW-c to the c2, and switch SW-d to the d1.Subsequently, when a new V-signal is input, the controlling section 10changes the position of the switch SW-a to the position a2, switch SW-bto the b1, switch SW-c to the c1, and switch SW-d to the d2. After that,when a new V-signal is input again, the controlling section 10 changesthe position of the switch SW-a to the position a1, switch SW-b to theb2, switch SW-c to the c2, and switch SW-d to the d1.

In sum, switching the state of each switch in the image processingsection 14 is to switch from/to one state (hereinafter, referred to as afirst state) to/from the other state (hereinafter, referred to as asecond state). The one state is a state in which the switch SW-a isclosed to the position a1, switch SW-b to the b2, switch SW-c to the c2,and switch SW-d to the d1. The other state is a state in which theswitch SW-a is closed to the position a2, switch SW-b to the b1, switchSW-c to the c1, and switch SW-d to the d2.

[Step S3]

The controlling section 10 starts the moving image capturing process.

[Step S4]

The controlling section 10 starts the transmittal between buffers.

[Step S5]

The controlling section 10 starts the moving image displaying process.

[Step S6]

The controlling section 10 starts performing the AE and AF.

[Step S7]

The controlling section 10 decides whether the release button ishalf-pressed or not. When the release button is half-pressed, thecontrolling section 10 proceeds to the operation in step S9. Otherwise,the controlling section 10 proceeds to the operation in step S8.

[Step S8]

The controlling section 10 decides whether the power supply switch isturned off or not. When the power supply switch is turned off, thecontrolling section 10 proceeds to the operation in step S22. Otherwise,the controlling section 10 returns to the operation in step S1.

Accordingly, while the power supply switch is in the on state, theoperations in steps S1 to S8 are repeated until the release button ishalf-pressed.

As a result, for example, when the switches in the image processingsection 14 are switched to the first state as shown in FIG. 4(a), newlygenerated moving image data is stored into the first buffer forphotographed image 31 as shown by a thick line in the drawing. Inaddition, the moving image data already stored in the second buffer forphotographed image 32 is transferred to the second buffer for displayimage 34, and the moving image data already stored in the first bufferfor display image 33 is displayed on the display device 16 through thedisplay controlling section 15.

When a new V-signal is input again and the switches in the imageprocessing section 14 are switched to the second state as shown in FIG.4(b), the moving image data which has been stored in the first bufferfor photographed image 32 in FIG. 4(a) is transferred to the firstbuffer for display image 34 as shown by a thick line in FIG. 4(b). Inaddition, newly generated moving image data is stored into the secondbuffer for photographed image 31, and the moving image data alreadystored in the second buffer for display image 33 is displayed throughthe display controlling section 15 on the display device 16.

Further, When a new V-signal is input again and the switches in theimage processing section 14 are switched to the first state as shown inFIG. 4(c), the moving image data which has been stored in the firstbuffer for display image 33 in FIG. 4(b) is displayed through thedisplay controlling section 15 on the display device 16 as shown by athick line in FIG. 4(c). In addition, newly generated moving image datais stored into the first buffer for photographed image 31, and themoving image data which has been stored in the second buffer forphotographed image 32 in FIG. 4(b) is transferred to the second bufferfor display image 34.

Consequently, in the process in which the operations in steps S1 to S8are repeated, displaying is performed while the operations of the imagesensor 13 and display device 16 are exactly synchronized each other. Inthis process, the moving image data stored into the first buffer forphotographed image 31 or the second buffer for photographed image 32 inthe moving image capturing process is displayed, delaying from the startof the data storage to the first buffer for photographed image 31 or thesecond buffer for photographed image 32 by two cycles of the V-signal.This delay corresponds to three cycles of the V-signal as in theconventional electronic camera if measured from a point at which theimage sensor 13 starts generating image signals associated with themoving image data. Hereinafter, this type of display, which is the sameas in the conventional electronic camera, is referred to as normaldisplay.

[Step S9]

This step follows step S7 when the release button has been half-pressedin step S7.

In this step, the controlling section 10 locks the AE and AF.

[Step S10]

The controlling section 10 decides whether a V-signal is input or not.The controlling section 10 repeats the operation in step S10 until aV-signal is input, and proceeds to the operation in step S11 in FIG. 3when the V-signal is input.

[Step S11]

The controlling section 10 decides whether the user has set a mode thatmakes a quick display (described in detail later) valid in advance. Whenthe mode that makes a quick display valid has been set, the controllingsection 10 proceeds to the operation in step S12; otherwise, thecontrolling section 10 proceeds to the operation in step S17.

[Step S12]

The controlling section 10 fixes the state of each switch in the imageprocessing section 14 to the state for the quick display. That is, thecontrolling section 10 fixes the switch SW-a to the position a1, switchSW-b to the b1, switch SW-c to the c3, and switch SW-d to the d3.

[Step S13]

The controlling section 10 starts the moving image capturing process.

[Step S14]

The controlling section 10 starts the moving image displaying process.Thus, when each switch in the image processing section 14 is fixed tothe state for the quick display as described above, the moving imagedata stored in the first buffer for photographed image 31 is directlysupplied to the display controlling section 15 without passing throughthe first buffer for display image 33 as shown by a thick line in FIG.5.

Moving image data newly stored in the first buffer for photographedimage 31 in the moving image capturing process can thus be displayed onthe display device more quickly than the normal display. Hereinafter,this type of display is referred to as quick display.

[Step S15]

The controlling section 10 decides whether the release button isfull-pressed or not.

When the release button is full-pressed, the controlling section 10proceeds to the operation in step S21; otherwise, the controllingsection 10 proceeds to the operation in step S16.

[Step S16]

The controlling section 10 decides whether the release button ishalf-pressed or not. When the release button is half-pressed, thecontrolling section 10 returns to the operation in step S10; otherwise(that is, when the press of the release button is released), thecontrolling section 10 returns to the operation in step S1.

Accordingly, while a mode in which the quick display is enabled is set,the operations in steps S10 to S16 are repeated to carry out continuousquick display as long as the release button is half-pressed.

[Step S17]

This step follows step S11 if the quick display mode is disabled. Thecontrolling section 10 changes the state of each switch in the imageprocessing section 14 as in step S2.

[Step S18]

The controlling section 10 starts the moving image capturing process asin step S3.

[Step S19]

The controlling section 10 starts the transmittal between buffers as instep S4.

[Step S20]

The controlling section 10 starts the moving image displaying process asin step S5 and then proceeds to the operation in step S15. Accordingly,when the quick display mode is disabled, the operations in steps S10,S11, S17 to S20, S15, and S16 are repeated to carry out the continuousnormal display as long as the release button is half-pressed.

[Step S21]

This step follows step S15 if the release button has been full-pressedin step SIS.

The controlling section 10 starts the still image recording process andthen returns to the operation in step S1. Accordingly, the operationsafter step 1 are repeated when the release button is full-pressed toperform the still image recording process or when the press of therelease button is released as described above.

[Step S22]

This step follows step S8 if the power supply switch has been turned offin step S8. The controlling section 10 performs a predetermined poweroff process and the operation of the controlling section 10 terminates.

The operation of the embodiment has been described above.

Effects of the Embodiment

According to the present embodiment, for using the moving image todetermine an image composition of an object, such as beforehalf-pressing the release button, the user can choose the normal display(steps S3 to S5), placing importance on a synchronization.

In another case, for using the moving image to determine a shootingtiming (full-pressing the release button), such as while half-pressingthe release button, the user can choose the quick display (steps S12 toS14), placing importance on a response feature. The normal display andthe quick display can thus be switched from each other appropriatelydepending on the features. Therefore, according to the embodiment, theuser can release the shutter at the right moment.

Supplemental Items of Embodiments

In the embodiment, an example has been described in which, when thequick display mode has been enabled, the normal display is switched tothe quick display if the release switch is half-pressed. The invention,however, is not limited to this embodiment.

As shown in FIG. 6 and FIG. 7, regardless of whether the release buttonis half-pressed or not, this switching may also be performed when theAE/AF lock switch is turned on.

Another example shown in FIG. 6 and FIG. 7 will be briefly describedbelow. Repeated descriptions of the above-described embodiment will beomitted here.

The controlling section 10 repeats the operations in steps S30 to S36 inFIG. 6 to perform the normal display until the AE/AF lock switch isturned on. When the AE/AF lock switch is turned on, then the controllingsection 10 locks the AE/AF function (step S37 in FIG. 6).

When the mode in which quick display is enabled is set in step S39, theoperations in steps S38 in FIG. 6 to S45 in FIG. 7 are repeated toperform the quick display until the release button is full-pressed.

When the mode in which quick display is not enabled is set in step S39,on the other hand, the controlling section 10 repeats the operations instep S38 in FIG. 6 and in steps S39, S46 to S49, and S43 to S45 in FIG.7 to perform the normal display.

When the release button is full-pressed while the quick or normaldisplay is performed after the AE/AF lock switch has been turned on, thecontrolling section 10 performs the still image recording process (stepS50 in FIG. 7); when the power supply switch is turned off, thecontrolling section 10 performs a power off process (step S51 in FIG.7).

Consequently, while the AE/AF lock switch is turned off, that is, it islikely that the user is using a moving image to determine an imagecomposition of an object, he/she can choose the normal display, placingimportance on a synchronization. While the AE/AF lock switch is turnedon, that is, it is likely that the user is using a moving image todetermine a shooting timing, he/she can choose the quick display,placing importance on a response feature. Therefore, in this embodiment,the same effects as in the above-described embodiment can also beobtained.

Relationship Between the Embodiment and the Claims

Finally, relationship between the embodiment and the claims will bedescribed. The following is an exemplary interpretation and does notlimit the invention.

A buffer section described in the claims corresponds to the first andsecond buffers for display image 33 and 34.

A recording section described in the claims corresponds to thecompressing/recording section 17.

A display switching section described in the claims corresponds to afunction of the controlling section 10 that switches the states of theswitches SW-a, SW-b, SW-c, and SW-d.

A first display described in the claims corresponds to the normaldisplay.

A second display described in the claims corresponds to the quickdisplay.

An operating member and the operating member being pressed in the firststep both described in the claims correspond to a release button and therelease button being half-pressed, respectively.

The phrase “predetermined timing” in the claims corresponds to a timingimmediately after the release button is half-pressed (when the mode inwhich quick display is enabled).

A shooting condition adjusting section described in claim 2 correspondsto a function of the controlling section 10 that performs the AE and AFin step S6.

The descriptions “user's operation to stop the auto exposure adjustment”in claim 3, “user's operation to stop the autofocus” in claim 4, and“user's operation to stop the auto exposure adjustment and theautofocus” in claim 5 correspond to the release button beinghalf-pressed (when the mode in which quick display is enabled).

The description “it is decided according to the user's operation whetheror not to enable the second display” in claim 6 corresponds to “afunction of the controlling section 10 that decides whether the user hasset a mode that makes a quick display valid in advance and proceeds tothe operation in step S12 or S17 depending on the decision” (see stepS11).

The invention is not limited to the above embodiments and variousmodifications may be made without departing from the spirit and scope ofthe invention. Any improvement may be made in part or all of thecomponents.

INDUSTRIAL AVAILABILITY

The electronic camera of the invention can properly display a movingimage that is usable as a viewfinder.

1. An electronic camera comprising: an image pickup sectionphotographing an object to generate an image; a display devicedisplaying the image generated by the image pickup section as a movingimage; a buffer section temporarily storing therein the image generatedby the image pickup section and to be displayed as a moving image on thedisplay device; and a recording section recording thereon the imagegenerated by the image pickup section according to a user's operation,wherein the electronic camera further comprises a display switchingsection which switches a first display and a second display at apredetermined timing, the first display being for performing display ofa moving image on the display device through the buffer section, thesecond display being for performing display of a moving image notthrough the buffer section.
 2. The electronic camera according to claim1, comprising: an operating member receiving a user's operation whenpressed in two steps, the user's operation being associated with theimage recording by the recording section; and a shooting conditionadjusting section performing at least one of auto exposure adjustmentand autofocus until the operating member is pressed in a first step,wherein the display switching section performs the first display untilthe operating member is pressed in the first step, and switches thefirst display to the second display when the operating member is pressedin the first step.
 3. The electronic camera according to claim 1,comprising: an exposure adjusting section performing auto exposureadjustment; and an operating member receiving a user's operation to stopthe auto exposure adjustment, wherein the display switching sectionperforms the first display until the user's operation to stop the autoexposure adjustment is received by the operating member, and switchesthe first display to the second display when the user's operation tostop the auto exposure adjustment is received.
 4. The electronic cameraaccording to claim 1, comprising: a focusing section performingautofocus; and an operating member receiving a user's operation to stopthe autofocus, wherein the display switching section performs the firstdisplay until the user's operation to stop the autofocus is received bythe operating member, and switches the first display to the seconddisplay when the user's operation to stop the autofocus is received. 5.The electronic camera according to claim 1, comprising: an exposureadjusting section performing auto exposure adjustment; a focusingsection performing autofocus; and an operating member receiving a user'soperation to stop the auto exposure adjustment and autofocus, whereinthe display switching section performs the first display until theuser's operation to stop the auto exposure adjustment and autofocus isreceived by the operating member, and switches the first display to thesecond display when the user's operation to stop the auto exposureadjustment and autofocus is received.
 6. The electronic camera accordingto claim 1, wherein: the display switching section decides whether ornot to enable implementation of the second display according to a user'soperation.